The best way to get to Kanyakumari from Madurai is via the National Highway 44. This route is very fast and all you need to do is follow the National Highway 44 till you reach your destination.
Kanyakumari is a beautiful hill station that is worth visiting all year around. Although the temperatures in summer could go up to 35 degrees it is usually not that hot. You will be able to travel around in comfort. If you are planning to come to Kanyakumari during the month of April to June then make sure to carry cool cotton clothes. This will keep you comfortable and you can travel easily. The monsoons in Kanyakumari are quite good which is why visiting Kanyakumari during the month of July to September would be best avoided. This could be a little difficult for you to get from one place to another. If you absolutely have to come to Kanyakumari during the monsoon time then make sure you rent an air conditioned cab. This will help you travel without having to face any obstacles. Winters are definitely the best time to come to Kanyakumari because the temperatures here drop considerably. This is an amazing sight to see.
The two routes from Madurai to Kanyakumari are pretty similar the travel time does not vary too much. You can get to Kanyakumari in four hours via the National Highway 44. You can also get to Kanyakumari in four and half hour via National Highway 38 and National Highway 44.
The road from Madurai to Kanyakumari is a straight road that you need to take and there is a national highway in between your journey. These roads are well maintained and you will be able to travel comfortably for the four hours on national highway 44. There are also some amazing things that you can do en route your journey which makes this road trip more fun.